1. Field of the Invention
The present invention relates to a fuel filter device of fuel heating type which is suitable for use in vehicles equipped with diesel engines.
2. Description of the Prior Art
The fuel used with diesel engines, i.e., light oil, tends to be solidified into wax-like state when cooled down below -10.degree. C., causing clogging of the fuel filter, which impairs the smooth operation of the engines due to insufficient supply of the fuel.
To obviate this problem, a fuel filter device has been proposed which has a heating element provided on the bottom of the filter container to heat the fuel therein. This type of filter is shown, for example, in U.S. Pat. No. 4,321,136.
This known filter device, however, has disadvantages that the size of the fuel filter device as a whole is increased and the structure is complicated because the filter container has to accomodate the heating element. In addition, this filter device cannot heat the fuel efficiently because the heating element indirectly heats the fuel either through the bottom wall of the filter container or through drain water accumulated on the bottom wall thereof.